Note 4 - Earnings Per Share (Details Textual) - $ / shares	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance (in shares)	0	0	13,000	12,150
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price, Ending Balance (in dollars per share)	$ 0	$ 0	$ 8.78	$ 8.78
Treasury Stock, Shares, Ending Balance (in shares)	1,275,465	1,275,465		929,362
Treasury Stock, Shares, Acquired (in shares)	165,058	346,103	58,200
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance (in shares)	77,933	77,933	67,760	66,362
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)		57,400	67,405

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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